Roof campers at ZG island

My guild was getting ready to drop a heart when one of us got frostbolted by this guy on the roof:

Some of us managed to find our way up there and take them down, so I decided to screenshot their names a little more closely for you guys.



Although there are no guards on ZG island, that still involves a spot a player cannot path to. Doesn't that make it an exploit?

Some of us managed to find our way up there and take them down, so I decided to screenshot their names a little more closely for you guys.



Although there are no guards on ZG island, that still involves a spot a player cannot path to. Doesn't that make it an exploit?